Plug.



G. W. NURGATE.

PLUG.

APmlcAioN FILED mures. |914.

Patented may 21,1918.

c stuntially 360 UNITED" STATES PATENT oEEicE. ,y

GEORGE W. NORGATE, OF CHICAGO, ILLINOIS, ASSIGNDR TO BENJAMIN ELECTRIC MANIL- FACTUBING COMPANY, F CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

PLUG.

To all whom vit may concern:

Be it known that I, GEORGE W. NoncA'rE, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Plugs, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

y invention relates to plugs or connecting devices and has for its obyect the provision of an improved connecting device for electric circuits adapted to establish circuit connections with the customary form of screw threaded socket.

y invention contemplates the provision of a plug having meansadapted lby the insertion of the plug within the socket to cause the enlargement or expansion of said means s'uiciently to engage the convolutions of the screw threaded portion of the socket, thereby to hold the plug in position. The structure is .suchthat the plug may be removed from the socket merely by exerting a strong pull against the plug, thus causing a contraction, of the means to permit the ready. withdrawal of the plug. v

,In he preferred form of my inventlon, I utilize as the expansible portion of the means a spring having the shape of a convolution ofca screw thread of the socket, which spring preferably extends throughout a portion'of the circumference of the plug subin order to get suiiicient contact for electrical purposes. The plug has a pair of relatively movable members, movement of which. in one direction causes theexpension of the said spring to enter the recess of the screw thread of the socket. If the plug is inserted into the socket so that the sprin and the depressed portion of a screw threa are not exactly superposed, then a slight rotationl of the plug is necessary to lock the plug in position as will be readily apparent from the description which will now be given of one -form which my improved plug may take in connection with the accompanying drawing illustrating such embodiment, in which- Figure 1 is a side view of a plug constructed in accordance with my invention shown in a socket? l2 is a longitudinal sectional view of mv `unprered plug, and

Specication of Letters Patent.

Application tiled June 28, 1914. Serial No. 847,885.

Patented May 21. 1 o1 e Fig. 3 is a View similar to Fig. 1 with'tlie pl as yet in its unlocked posltion.

y improvedvplug has two relatively mov able members respectively 1 and 2. `The member 2 has a central contact 3 mounted thereon which is in electrical association with one of the lead in wires 4 through the agency of the binding screw `5, as'readily apparent. The parts 1 and 2 are held together by the screw 6 so that when the' screw 6 is removed the lead in wires 4 and 7 can be readily attached to the binding screws and 8. The portion 1 has an annular plate therefor which is flaring as shown at 9 upon which flaring portion and the straight extension 1D thereof, a spring 11 is adapted to be slid from the contracted position of Fig. 3 to the expanded position shown in Figs. 1 and 2. When the plug is pushed into the socket 12 the plate 2 moves inwardly relatively to the part 1, thereby pushing the spring ring 11 ove the ,daring or diverging portion 9 so that this spring is expanded to enter one of the recesses of the screw threaded portion 13 ofthe socket, `thus' to hold the plug in position.l i

It will be noted that -when the plug is in drical portion so that it does not tend of itself to move 'into the position whereby it encircles the portion of restricted diameter as at 9. Now when a piill however is ea erted against the part 1 of Fig. 1. then part 1 moves outwardly, leaving the ring l1 behind, thus sliding it along the'portion 10 and ermitting it to ride downwardly over the aring portion 9 so that this ring contracts into the position 'shown in Fi 3, under which conditions this ring 11 c ears the screw threaded portions of the socket.

lThe plug mav thus be withdrawn by merel y exerting a pull against the element 1. Electrical contact is effected between the screw threaded element of the plug and the conductor 7 Vthrough the agency of the contact striprll with w ich said ring engages and by having the ring 11 engage the conducting strip 15, mounted within the plate 1, which conducting strip through the agency of the screw 6v is in electrical contact with the conductincg vplate 13 to which the screw 8 is secure The contact thus is of substantial nature as the element Msldes over thevplatel when being locked position, th,ueinser.--

' place the element 11 is upon astraight cylin- IOL substantially 360o of the circumference of the plu and has the shape and pitch of the ,screw t read of the socket.

From what has been described it is thou ht the nature of m invention will be readl clear to those ski led in the art, and what il therefore claim as new and desire te Secure by Letters Patent is:

1. A connecting plug of the character described having two relatively movable members, and a spring having a shape conforming to the pltch of the screw thread of a. socket mounted upon the periphery of one of said members controlled by the relative movement between said members to increase its diameter for engagement With said screw thread or decrease it sufficiently to allow it to be drawn from said'socket without rotation.

2. A connecting plug of the character described having two relatively movable members, and a spring having a shape conforming-to the pitch of the screw thread of a socket mounted upon the periphery of one of said members and cam shaped means over which said spring is movable by the relative movement between said plug members to increase its diameter for engagement with the screw thread of a socket or to decrease its diameter sufficiently to allow it to be withdrawn from said socket Without rotation.

3. A plug of the character described having two relatively movable members, one of said members protruding when the plug is movement of said members to enlarge or reduce said spring contact sulciently to allow it to be withdrawn from the screw threads" off socket without rotation to thereby cause y it te engage er disenga e from the screw' threaded portion of a soc et, said means permitting a disconnection of the lug from the socket when a ull is excrte against the protruding mem er of said plug.

4. A plug of the character described having two relatively movable members, one of sald members protruding when the plug is in position wit 1 respect to a socket, a spring contact, and means controlled by the relative movement of said members to enlarge or reduce said spring contact to increase its diameter for engagement with the screw threads of a socket or to decrease its diameter sufficiently to allow it to be withdrawn from said socket without rotation to thereby cause it to engage or disengage from the screw threaded portion of a socket', said means permitting a disconnection of the plu from the socket when a pullis exerted against the protruding niember of said plug,

by causing a relative movement between said` protruding member and said spring Contact'. In witness whereof, I hereunto subscribe my name this 23rd dayof June, A.D. 1914A.'

GEORGE W. NORGATE.

Witnesses:

MAX W. ZABEL., HAzEL. ANN JONES. 

